1804 Silver dollar, “Original” or Class 1, PR65 (PCGS grade, two coins) - $5,500,000.
There are two examples of the 1804 silver dollar that have
been graded PR65 by PCGS. These are the Eckfeldt-Stickney-Atwater-Eliasbergspecimen and the Dexter-Dunham-Bareford specimen. PCGS coin # 6907

1804 Draped Bust $10 gold piece Proof, PR65DCAM (estimated grade) - $4,750,000.
The 1804 $10 gold proofs were struck at the same time as the “Original, Class I” 1804 silver dollars,
i.e. beginning in 1834. One example is still in the King of Siam proof set. Four proofs were originally
struck. It is unclear whether three of the four or all four exist today. The highest-graded example
recently changed hands at close to $5 million.
PCGS coin # 8570

1913 Liberty nickel, PR66 (PCGS grade) - $4,500,000.
This is the finest of the five known examples of what is arguably the most famous United States rare coin.
It is the Colonel Green-Louis Eliasberg specimen.
PCGS coin # 3912